Introducing the methods of geoscience to physical geology students

Beth Dushman, Natural Sciences, Del Mar College

As a geology instructor at a community college, I teach mostly non-majors students in my Physical Geology lectures and labs. These classes may be these students' only introduction to science at a college level, and it may be the first science class they have had in years. These students are often science-phobic and lack the confidence to engage in discovery learning. At the same time, I often have a few majors in my classes. Thus, my challenge is to teach the majors geoscience skills they will need for future classes, while engaging the rest of the class in activities that will improve their understanding of basic science and geology. The most important methods of geoscience that I think students should learn in my classes are critical reasoning, observation of natural phenomena, synthesis of multiple ideas, the basics of how the scientific method is applied in geology, and communicating scientific information.

I use a variety of strategies to teach these science methods in my lecture and laboratory classes. I start each semester with an overview of the scientific method, and compare the traditional 5-step process (observation, hypothesis, experimental design, data collection and analysis, and conclusion) to how the scientific method is applied in Geology. For example, many students learn that science is conducted through experiments with strict controls and a few variables. Geoscientists, however, lack an extra planet to use as a control when we study the Earth. Instead, we make approximations in labs and using computer models, but often data are gathered through field observations.

As the class investigates various topics in geology, I explicitly identify ways in which the scientific method (and other geoscience methods) has improved our understanding of the Earth. The development of the theory of plate tectonics works an an excellent example. We discuss the initial observations, gathering of evidence, original ideas and criticisms about continental movement, through the discoveries that resulted in the theory of plate tectonics. Throughout the semester, I encourage students to ask, "how do we know that?" about any topic. Each time this question is raised, it presents an opportunity to share the observational and analytical methods that laid the foundation for our current understanding of that geological phenomenon.

Of all the science methods my students should learn, critical reasoning skills are the most important. Critical reasoning is essential in most fields, and yet students are often overwhelmed by any problem that requires effort beyond simple memorization and regurgitation. This problem may be compounded by the perception that science is too hard, or that students are "bad at science." As a way to demonstrate to my students that they can be competent problem solvers, I work with them to break problems down into simple steps, and then to integrate those steps to make a whole story. For example, while interpretation of a simple stratigraphic section may be daunting at first, students gain confidence as they decipher the geological history of that area.

In my lab classes, students apply some of these methods through hands-on experimentation. For example, students practice observation of natural phenomena in lab exercises using stream tables and Google Earth, while simultaneously synthesizing information from lecture, lab, and observations. As part of the lab where students experiment with small stream tables, students are asked to describe how the models succeed or fail at approximating Earth processes. This question helps to engage students in a discussion of the limitations and advantages of using models in geoscience in general.

Another important geoscience method is clearly and effectively communicating scientific information. My students complete a writing assignment for which they must find and evaluate sources of scientific information, then summarize into a coherent synopsis of a significant geologic event. This exercise introduces students to how scientists collect, interpret, and communicate their data. While the students are not conducting original research for these assignments, this project may be their first introduction to scientific reseach. Furthermore, by delving deeper into the information available for a given geologic event, students begin to recognize the differences between scientific media and popular media. For majors, this project gives students an idea of where to start looking for science resources and introduces them to the peer-review process. For nonmajors, students gain an appreciation for how scientific information is developed and disseminated to public.

Prior to taking this class, many students were only exposed to geology when natural disasters occurred, resulting in a somewhat skewed perception of the role geologists play in forecasting or mitigating these events. By developing a deeper understanding of the ways in which geoscientists study the earth, students are better able to assess the information they see in the mainstream media. To this end, we discuss methods geologists employ to study hazards, such as seismic surveys, mapping of earthquake foci, gravitational studies, and volcanic hazards monitoring, and how geologists describe risk using recurrence intervals. Then, when we address the limitations of these methods as applied to natural hazards, students recognize why we cannot predict or prevent many geological events.

Lastly, any discussion of how science works should include a discussion of how scientific thought changes over time. I emphasize that while geologists do have a very strong framework for contextualizing most Earth processes– Plate Tectonics– there is still a lot about how the Earth works that we do not yet understand. As students consider applications of geoscience methods to these unanswered questions about the Earth, they gain an appreciation for ongoing geological research. Even better, some are inspired to become geoscientists themselves.

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